1. Field
The invention is in the field of keyboards used for typewriters, computers, or the like for data entry or other control purposes.
2. State of the Art
It has long been recognized that the traditional "universal" (qwerty) typewriter keyboard has many defects in terms of the ease of learning and of the accuracy and efficiency of data entry. In fact, according to most historians, this particular arrangement of letters and control keys was deliberately designed to help prevent the jamming of the typebars in early mechanical typewriters by placing the most commonly used letters far apart from each other in the typebasket. It has further been suggested that the letters for the word "typewriter" were all deliberately put in the top row to make it easy for a salesman to quickly type out the name of this new machine while demonstrating its abilities to skeptical clients.
Also, certain basic ergonomic principles that would have maximized workstation productivity and accuracy while minimizing operator fatigue were not taken into account in the design of the universal keyboard; instead, basic mechanical requirements of the early machines usually overruled any conflicting human engineering considerations. Unfortunately, this particular keyboard design became the universal standard before the advent of touch typing for which it is particularly unsuited since:
1. More of the commonly used letters are on the top row than on the home row where the fingers normally rest.
2. Some of the most frequent stroking actions must be done by the weakest fingers.
3. The left hand executes more strokes and completes more complex finger movements than the right hand even though most users are right-handed.
4. The straight horizontal rows of keys interface poorly with human arms, hands, and fingers resulting in unnecessary operator stress and fatigue.
5. The head must be constantly turned to the left or right to read the material being typed, thereby increasing the chance of making errors and of operator fatigue.
6. The staggering of keys on adjacent horizontal rows requires more complex hand-finger movement than if the keys had been also aligned vertically.
As Yamada in his very comprehensive papers, "A Historical Study of Typewriters and Type Methods: from the Position of Planning Japanese Parallels" (Journal of Information Processing, Vol. 2, No. 4, pp. 175-202, February 1980) and "Certain Problems Associated with the Design of Input Keyboards for Japanese Writing" in Cognitive Aspects of Skilled Typewriting, William E. Cooper, 1983 ed., pp. 305-407, clearly demonstrates and as I have discovered in a search of issued patents and of the literature, inventors beginning at least in the year 1870 became aware of these problems and have tried to correct these deficiencies by such means as:
1. Splitting the keyboard into two separate halves.
2. Curving the key rows to fit the hand.
3. Varying the height, location, and/or shape of keys and the keyboard itself to match various characteristics of the different fingers and the hands themselves.
4. Moving shift and other control keys from the weaker to the stronger fingers.
5. Moving the most commonly used letters to the home row.
6. Using the feet to perform shift and control functions.
7. Moving the most commonly used letters to the strongest fingers.
8. Using linguistic and motion study analyses to determine the most efficient placement of keys.
9. Using multiple, simultaneous key strokes to reduce the number of keys required to produce a full set of characters and to reduce the needed finger and hand and/or arm motion needed to produce such characters, for example, the use of the shift key to produce upper and lower case letters.
10. Using finger guides to insure proper location of fingers for touch typing.
11. Moving the most frequently occurring consecutive symbols to different fingers or hands.
12. Providing for the single stroke entry of symbols representing whole syllables.
13. Allowing common two or more letter combinations to be entered by striking the two or more keys simultaneously.
14. Use of a double threshold key to eliminate the need for a shift key.
15. Use of a two or more stroke (in sequence) entry system to simplify the entry of the hundreds or thousands of symbols needed to type a nonphonetic written language.
In reference to recently suggested systems, D'Angiolillo et al. (U.S. Pat. No. 4,310,254) designed a keyboard to provide for the single stroke entry of symbols representing syllables. This provided a more efficient mechanical shorthand device to record court proceedings, etc. Only 33 keys are needed for his machine, rather than the usual 50. However, the shorthand code produced has to be retyped again for a reader not familiar with the code.
Einbinder (U.S. Pat. No. 3,945,482) changed the traditional keyboard to allow common two letter combinations to be entered by striking the two keys simultaneously and tried to arrange the keys to maximize alternate left-hand and right-hand input. However, it would take an operator some time to learn which two letter combinations could be entered in this fashion. For example, if the keys "s" and .intg.t" were struck simultaneously, a person must learn if the result will be "st" or "ts". The newly announced "Velotype" keyboard is said to solve this problem through the use of a very fast computer with an enormous memory of the probability of occurance of different letter combinations in varying syntactic contexts, so that the letter combinations for whole syllables can be entered simultaneously in a manner similar to the way in which a piano chord is played. This is a modification of an early suggestion to use a piano-type keyboard. Michael Adler in his 1973 book, The Writing Machine, states that such a keyboard should be modified so that certain control actions, such as spacing and shifting from lower to upper case letters, can be done using foot switches. With such a keyboard, Adler suggests that the typist could approach the pianist's "data-entry" speed of over 1,500 to 2,000 strokes a minute (the equivalent of 300-400 words per minute). Three problems with such a suggestion immediately arise, namely, the large size of such a keyboard, although Cuau (1978 French Patent No. 2,376,480) suggests a way that a more compact piano-type keyboard can be constructed, as do also the developers of the "Velotype" keyboard which uses only 37 keys, the fact that the pianist's greatest speed is usually only achieved by playing memorized materials, a situation that occurs very rarely in ordinary typing behavior, and the difficulty of precisely synchronizing foot and finger movements.
Malt (U.S. Pat. No. 4,244,659) has organized the keys so that in order to provide high speed operation, the most frequently used symbols are operated by the strongest fingers, and the most frequently occurring consecutive symbols are operated by different fingers. A one-handed version is also described. However, in assigning the letters to the strongest fingers, Malt has actually lost much of the potential input speed due to alternating left-hand and right-hand stroking.
The ultimate reduction in number of keys and finger movements away from the home row occurs in Cy Enfield's "Microwriter", first marketed in 1978, which used only six keys to generate the entire alphabet and the most common punctuation marks. A mnemonic system is used to train the operator to know which keys must be pressed simultaneously to generate given characters. However, in spite of the inventor's claim that these combinations of keystrokes are easy to memorize, the lack of visual cues to character generation on the keyboard makes it impossible for the novice to operate. Also, the fact that it is a one-handed keyboard limits the ultimate typing speed that can be achieved, as does also the number of relatively awkward combinations of finger strokes needed to generate certain characters.
The most recent research, as found in the articles "The Skill of Typing" by Timothy A. Salthouse, Scientific American, February 1984, pages 128-135, "The Typist's Touch" by Donald A. Norman, Psychology Today, March 1984, Pages 66-72, and the above referenced Yamada papers, indicates that, since most skilled touch-typists begin the movement of fingers toward the striking positions as early as seven spaces before the actual key depression occurs, typing speeds slow when:
1. The same finger must be used to produce a two or three letter sequence.
2. More than one key must be depressed at one time (chording, shifting).
3. A key must be visually located because of either infrequent usage or the presence of too many keys on the keyboard.
4. The fingers must make large or awkward jumps on the keyboard away from their home positions.
While many different keyboards have been suggested by the prior art, there remains a need for a keyboard that not only takes into consideration the above factors but provides for increased speed of data entry and ease of use.